A particular prior art circuit for converting a first differential input signal into an output signal is known from US 2005/0258901.
A general prior art circuit for converting a first differential input signal into an output signal is an operational amplifier. To create a circuit for converting first and second differential input signals into an output signal, three operational amplifiers may be required. A first operational amplifier converts the first differential input signal into a first intermediate signal, and a second operational amplifier converts the second differential input signal into a second intermediate signal, and a third operational amplifier converts the first and second intermediate signals into the output signal. Usually, common mode feedback circuitry coupled to the outputs of the first and second operational amplifiers may further be required for controlling these first and second operational amplifiers.
The prior art circuit for converting first and second differential input signals into an output signal is disadvantageous, inter alia, owing to the fact that it is relatively complex.